The original gb and ds came out in a different time. Mobile gaming is extremely popular. No handheld is going to sell a 100 million again
Still GBA would've likely sold over 100 million fairly easily itself had it not been prematurely pushed off the market.
That said, yes the portable market has obviously changed. But Switch is a different kind of product too and is reaching demographics the GBA could not.
There are also things Nintendo could do with the Switch hardware ecosystem IMO that compound sales, like I do think there will be a mid-gen Switch refresh around 2020 (current Switch will then be redesigned on 16nm eventually and aimed more at kids eventually, newer Switch model will continue to serve the lucrative higher end market at $300).